<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
    <title>小黑记事本</title>
    <link rel="stylesheet" type="text/css" href="./css/Bookindex.css" />
  </head>

  <body>
  <!-- 主体区域 -->
  <section id="todoapp">
    <!-- 输入框 -->
    <header class="header">
      <h1>记事本</h1>
      <input autofocus="autofocus"
             autocomplete="off"
             placeholder="请输入任务"
             class="new-todo"
             v-model="message"
             @keyup.enter="add" />
    </header>
    <!-- 列表区域 -->
    <section class="main">
      <ul class="todo-list">
        <li class="todo" v-for="(item,index) in msg">
          <div class="view">
            <span class="index">{{ index+1 }}.</span>
            <label>{{ item }}</label>
            <button class="destroy" @click="remove(index)"></button>
          </div>
        </li>
      </ul>
    </section>
    <!-- 统计和清空 -->
    <footer class="footer" v-show="msg.length!=0">
      <span class="todo-count" v-if="msg.length!=0">
        <strong>{{msg.length}}</strong> items left
      </span>
      <button class="clear-completed" @click="clear">
        Clear
      </button>
    </footer>
  </section>
  </body>
  <script src="../js/vue.js"></script>
  <script>
    let app = new Vue({
      el: "#todoapp",
      data: {
        msg: ["吃饭饭", "打豆豆"],
        message: "",
      },
      methods: {
        add() {
          this.msg.push(this.message)
        },
        remove(index) {
          this.msg.splice(index, 1);
        },
        clear() {
          this.msg = [];
        }
      }
    })
  </script>
</html>
